Recent years have witnessed an increasing number of liquid crystal display devices in use. A liquid crystal display device includes a display panel for displaying an image. A display panel includes, provided therein, a liquid crystal driving circuit for driving liquid crystal.
A display panel includes a plurality of pixels, each of which includes liquid crystal and a thin film transistor (TFT) for driving the liquid crystal.
A display panel further includes: gate bus lines each for supplying a gate signal (in the form of a pulse) to the gate electrode of a thin film transistor; and data bus lines each for supply a data signal to the source electrode of a thin film transistor. A thin film transistor includes a drain electrode connected to a corresponding pixel electrode. A thin film transistor is switched between a non-conductive state and a conductive state in correspondence with the value of the gate signal. A data signal to a data bus line is supplied to a pixel electrode only when the corresponding thin film transistor is in the conductive state.
A gate bus line normally has an internal resistance and an internal capacitance. These internal resistance and internal capacitance cause the pulse of a gate signal propagating through a gate bus line to have an edge with a distortion (round-off) corresponding to the distance over which the gate signal propagates through the gate bus line. A gate signal, in particular, has a longer tail in correspondence with a longer distance over which the gate signal propagates through a gate bus line.
Such a tail problematically causes a thin film transistor to supply a data signal to its corresponding pixel electrode at a timing at which the thin film transistor is supposed to block such a data signal.
Patent Literature 1 discloses (i) a system for driving a liquid crystal display device, the system including delaying means for delaying a source signal (data signal) for each source line (data bus line) and (ii) a system for driving a liquid crystal display device, the system including delaying means for delaying a gate signal for each gate line (gate bus line).
The technique disclosed in Patent Literature 1, however, provides the delaying means to each data bus line or each gate bus line, and thus problematically leads to a complicated configuration for a liquid crystal driving circuit provided to the display panel.
There has conventionally been known a two-sided driving system that (i) provides a liquid crystal driving circuit on each side of the display section of a display panel and (ii) supplies a gate signal to a gate bus line from both ends thereof. This system prevents a tail in the pulse of a gate signal. This system, however, requires a large space, for providing a liquid crystal driving circuit, on each side of the display section of a display panel. This system is thus problematic in that it is difficult to apply to a liquid crystal display device, such as a portable liquid crystal terminal, for which it is essential to reduce space that it takes up.
Japanese Patent Application Publication, Tokukai, No. 2000-242241 A (Publication Date: Sep. 8, 2000)